92,000 households are being recruited for the Online Energy Saving Account (ESA) of the Minus 40 Per Cent Club. The software calculates the CO2 figures for the heating energy and electricity consumption figures read off and records how the minus 40 per cent target (1990-2020) is achieved and exceeded. Participants are reducing their CO2 emissions by an average of 1.69 % p.a. Interim results, examples and solutions to problems are communicated on an ongoing basis. An in-depth study is being carried out of a thousand households with internal energy production (photovoltaics, CHP) and another thousand with automated monitoring. In just under two-and-a-half years from September 2008 the number of ESAs was increased from 8,000 to 100,000 by means of partnerships, for example with energy utilities, and media work. Online and e-mail consultations provide motivation by means of benchmarks, individual cost reduction potential, etc. Both reasons for success and problems are being identified for 1,000 ESA users as well as for the 1,000 users of automatic monitoring and for the 100 users of building energy management. The federal government is demonstrating the achievability of its target of a 40 % cut in CO2 from 1990 to 2020.